The vertical profile of atmospheric heating rate of black carbon aerosols at Kanpur in northern India

• Published in: Atmospheric environment (1994) Vol. 41; no. 32; pp. 6909 - 6915
• Main Authors: Tripathi, S.N., Srivastava, Atul K., Dey, Sagnik, Satheesh, S.K., Krishnamoorthy, K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2007; Elsevier Science
• Subjects: Applied sciences; Atmospheric pollution; Black carbon profile; Exact sciences and technology; Heating rate; Northern India; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Asia; India; Uttar Pradesh; India, Uttar Pradesh, Unnao Dist., Kanpur; Pollution; Black carbon profile; Heating rate; Northern India; Combustion residue; Carbonaceous materials; Visa; Summer; Environmental factor; Measurement campaign; Urban area; Time variation; Turbulent mixing; Winter; Seasonal variation; Atmospheric boundary layer; Aircraft observation; Aerosols; Air pollution; Concentration distribution; Altitudinal distribution
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2007.06.032

Altitude profiles of the mass concentrations of aerosol black carbon (BC) and composite aerosols were obtained from the collocated measurements of these quantities onboard an aircraft, over the urban area of Kanpur, in the Ganga basin of northern India during summer, for the first time in India. The enhancement in the mean BC concentration was observed at ∼1200 m in the summer, but the vertical gradient of BC concentration is less than the standard deviation at that altitude. The difference in the BC altitude profile and columnar concentration in the winter and summer is attributed to the enhanced turbulent mixing within the boundary layer in summer. This effect is more conspicuous with BC than the composite aerosols, resulting in an increase in the BC mass fraction ( F BC) at higher levels in summer. This high BC fraction results in an increase in the lower atmospheric heating rate in both the forenoon, FN and afternoon, AN, but with contrasting altitude profile. The FN profile shows fluctuating trend with highest value (2.1 K day −1) at 300 m and a secondary peak at 1200 m altitudes, whereas the AN profile shows increasing trend with highest value (1.82 K day −1) at 1200 m altitude.